Removal of nitric oxide from flue gas using novel microwave -activated double oxidants system

A novel microwave-activated H2O2/PS (persulfate) double oxidants system was developed for NO removal from flue gas. Several experiments and characterization were conducted to study several fundamental issues of NO removal using the developed microwave-activated H2O2/PS oxidation system (e.g., optimizing technological parameters, determining free radicals and products, and revealing NO removal mechanism). Free radical identification experiments showed that several synergistic activation effects were found in the developed microwave-activated H2O2/PS oxidation system. SO4−·, ·OH, HO2·, H2O2 and PS were considered to be the active species for the NO removal, and ·OH played a leading role. The product and by-product such as nitrate, sulfate and NO2 from tail gas were determined quantitatively. Increasing microwave power, concentration of H2O2 and PS, and O2 content enhanced the NO removal. Increasing NO and SO2 concentration, solution pH value, and flue gas flow rate weakened the NO removal. Reaction temperature and reagent flow rate showed a double effect on the NO removal. © 2020 Elsevier B.V.